On a current optical transport network, a wavelength division multiplexing system includes the following key components: an optical transmitter that converts to-be-transmitted information into an optical signal; a receiver that converts a received optical signal into an electrical signal; and a wavelength division multiplexer/demultiplexer that converges multi-wavelength optical signals generated by multiple local transmitters to a feeder fiber connecting to another node and that distributes multi-wavelength optical signals, from the another node, on the feeder fiber to multiple receivers. Generally, one optical transmitter and one optical receiver are encapsulated together and referred to as an optical module.
A wavelength division multiplexing device generally includes a chassis and a line card inserted into the chassis. In a prior art, a wavelength division multiplexer/demultiplexer is disposed on a line card, an optical module is disposed on another line card, and the optical module and the wavelength division multiplexer/demultiplexer are connected by an optical fiber between the line cards; in another prior art, an optical module is disposed on a line card, a wavelength division multiplexer/demultiplexer is disposed within a module outside a chassis, and the optical module and the wavelength division multiplexer/demultiplexer are connected by an optical fiber.
In a process of implementing embodiments of the present invention, the prior art has the following disadvantages: space utilization of an optical network device is low, because optical fiber connection between line cards and between a line card and an external module is complex, and management difficulty is relatively high.